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Daniel Mazur

Publications and source records attributed to Daniel Mazur.

4 recordsLinked to original sources
arXiv2007

Characteristic Energy of the Coulomb Interactions and the Pileup of States

Tunneling data on $\mathrm{La_{1.28}Sr_{1.72}Mn_2O_7}$ crystals confirm Coulomb interaction effects through the $\sqrt{\mathrm{E}}$ dependence of the density of states. Importantly, the data and analysis at high energy, E, show a pileup of states: most of the states removed from near the Fermi level are found between ~40 and 130 meV, from which we infer the possibility of universal behavior. The agreement of our tunneling data with recent photoemission results further confirms our analysis.

cond-mat.str-el↗
arXiv2007

Evidence of Strong-Coupled Superconductivity in CaC6 from Tunneling Spectroscopy

Point-contact tunneling on CaC$_6$ crystals reproducibly reveals superconducting gaps, $Δ$, of 2.3$\pm$0.2 meV which are $\sim$~40% larger than earlier reports. That puts CaC$_6$ into the class of very strong-coupled superconductors since 2$Δ$/kT$_c\sim$~4.6. Thus soft Ca phonons will be primarily involved in the superconductivity, a conclusion that explains the large Ca isotope effect found recently for CaC$_6$. Consistency among superconductor-insulator-normal metal (SIN), SIS and Andreev reflection (SN) junctions reinforces the intrinsic nature of this result.

cond-mat.supr-con↗
arXiv2006

Tunneling spectroscopy of Tl2Ba2CaCu2O8 single crystals and thin films

Early electron tunneling experiments with the Tl2Ba2CaCu2O8 measured Δ= 16-28 meV, while bulk optical experiments measured Δ= 43-45 meV. We report new tunneling measurements of Tl2Ba2CaCu2O8 single crystals and c-axis oriented thin films, where the measured Δvalues on both sample types cover the range of 24-50 meV, with more than 70% of the junctions displaying Δ> 30 meV. This work resolves the inconsistency between previously published results of tunneling and optical experiments. New tunneling conductances reveal improved superconducting gap region characteristics consistent with d-wave symmetry. The tunneling spectra also display features similar to the dip feature observed in Bi2Sr2CaCu2O8. We discuss our results in context of experiments reported previously on related materials.

cond-mat.supr-con↗